1 // SPDX-License-Identifier: GPL-2.0+
3 * FB driver for the ST7735R LCD Controller
5 * Copyright (C) 2013 Noralf Tronnes
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <video/mipi_display.h>
15 #define DRVNAME "fb_st7735r"
16 #define DEFAULT_GAMMA "0F 1A 0F 18 2F 28 20 22 1F 1B 23 37 00 07 02 10\n" \
17 "0F 1B 0F 17 33 2C 29 2E 30 30 39 3F 00 07 03 10"
19 #define ADAFRUIT18_GAMMA \
20 "02 1c 07 12 37 32 29 2d 29 25 2B 39 00 01 03 10\n" \
21 "03 1d 07 06 2E 2C 29 2D 2E 2E 37 3F 00 00 02 10"
23 static const s16 default_init_sequence[] = {
24 -1, MIPI_DCS_SOFT_RESET,
27 -1, MIPI_DCS_EXIT_SLEEP_MODE,
30 /* FRMCTR1 - frame rate control: normal mode
31 * frame rate = fosc / (1 x 2 + 40) * (LINE + 2C + 2D)
33 -1, 0xB1, 0x01, 0x2C, 0x2D,
35 /* FRMCTR2 - frame rate control: idle mode
36 * frame rate = fosc / (1 x 2 + 40) * (LINE + 2C + 2D)
38 -1, 0xB2, 0x01, 0x2C, 0x2D,
40 /* FRMCTR3 - frame rate control - partial mode
41 * dot inversion mode, line inversion mode
43 -1, 0xB3, 0x01, 0x2C, 0x2D, 0x01, 0x2C, 0x2D,
45 /* INVCTR - display inversion control
50 /* PWCTR1 - Power Control
53 -1, 0xC0, 0xA2, 0x02, 0x84,
55 /* PWCTR2 - Power Control
56 * VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD
60 /* PWCTR3 - Power Control
61 * Opamp current small, Boost frequency
65 /* PWCTR4 - Power Control
66 * BCLK/2, Opamp current small & Medium low
70 /* PWCTR5 - Power Control */
73 /* VMCTR1 - Power Control */
76 -1, MIPI_DCS_EXIT_INVERT_MODE,
78 -1, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_16BIT,
80 -1, MIPI_DCS_SET_DISPLAY_ON,
83 -1, MIPI_DCS_ENTER_NORMAL_MODE,
90 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
92 write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
93 xs >> 8, xs & 0xFF, xe >> 8, xe & 0xFF);
95 write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
96 ys >> 8, ys & 0xFF, ye >> 8, ye & 0xFF);
98 write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
101 static void adafruit18_green_tab_set_addr_win(struct fbtft_par *par,
102 int xs, int ys, int xe, int ye)
104 write_reg(par, 0x2A, 0, xs + 2, 0, xe + 2);
105 write_reg(par, 0x2B, 0, ys + 1, 0, ye + 1);
106 write_reg(par, 0x2C);
112 static int set_var(struct fbtft_par *par)
114 /* MADCTL - Memory data access control
116 * 1. Mode selection pin SRGB
117 * RGB H/W pin for color filter setting: 0=RGB, 1=BGR
119 * RGB-BGR ORDER color filter panel: 0=RGB, 1=BGR
121 switch (par->info->var.rotate) {
123 write_reg(par, MIPI_DCS_SET_ADDRESS_MODE,
124 MX | MY | (par->bgr << 3));
127 write_reg(par, MIPI_DCS_SET_ADDRESS_MODE,
128 MY | MV | (par->bgr << 3));
131 write_reg(par, MIPI_DCS_SET_ADDRESS_MODE,
135 write_reg(par, MIPI_DCS_SET_ADDRESS_MODE,
136 MX | MV | (par->bgr << 3));
144 * Gamma string format:
145 * VRF0P VOS0P PK0P PK1P PK2P PK3P PK4P PK5P PK6P PK7P PK8P PK9P SELV0P SELV1P SELV62P SELV63P
146 * VRF0N VOS0N PK0N PK1N PK2N PK3N PK4N PK5N PK6N PK7N PK8N PK9N SELV0N SELV1N SELV62N SELV63N
148 #define CURVE(num, idx) curves[(num) * par->gamma.num_values + (idx)]
149 static int set_gamma(struct fbtft_par *par, u32 *curves)
154 for (i = 0; i < par->gamma.num_curves; i++)
155 for (j = 0; j < par->gamma.num_values; j++)
158 for (i = 0; i < par->gamma.num_curves; i++)
159 write_reg(par, 0xE0 + i,
160 CURVE(i, 0), CURVE(i, 1),
161 CURVE(i, 2), CURVE(i, 3),
162 CURVE(i, 4), CURVE(i, 5),
163 CURVE(i, 6), CURVE(i, 7),
164 CURVE(i, 8), CURVE(i, 9),
165 CURVE(i, 10), CURVE(i, 11),
166 CURVE(i, 12), CURVE(i, 13),
167 CURVE(i, 14), CURVE(i, 15));
174 static struct fbtft_display display = {
178 .init_sequence = default_init_sequence,
181 .gamma = DEFAULT_GAMMA,
183 .set_addr_win = set_addr_win,
185 .set_gamma = set_gamma,
189 int variant_adafruit18(struct fbtft_display *display)
191 display->gamma = ADAFRUIT18_GAMMA;
195 int variant_adafruit18_green(struct fbtft_display *display)
197 display->gamma = ADAFRUIT18_GAMMA;
198 display->fbtftops.set_addr_win = adafruit18_green_tab_set_addr_win;
202 FBTFT_REGISTER_DRIVER_START(&display)
203 FBTFT_COMPATIBLE("sitronix,st7735r")
204 FBTFT_COMPATIBLE("fbtft,sainsmart18")
205 FBTFT_VARIANT_COMPATIBLE("fbtft,adafruit18", variant_adafruit18)
206 FBTFT_VARIANT_COMPATIBLE("fbtft,adafruit18_green", variant_adafruit18_green)
207 FBTFT_REGISTER_DRIVER_END(DRVNAME, &display);
209 MODULE_ALIAS("spi:" DRVNAME);
210 MODULE_ALIAS("platform:" DRVNAME);
211 MODULE_ALIAS("spi:st7735r");
212 MODULE_ALIAS("platform:st7735r");
213 MODULE_ALIAS("spi:sainsmart18");
214 MODULE_ALIAS("platform:sainsmart");
215 MODULE_ALIAS("spi:adafruit18");
216 MODULE_ALIAS("platform:adafruit18");
217 MODULE_ALIAS("spi:adafruit18_green");
218 MODULE_ALIAS("platform:adafruit18_green");
220 MODULE_DESCRIPTION("FB driver for the ST7735R LCD Controller");
221 MODULE_AUTHOR("Noralf Tronnes");
222 MODULE_LICENSE("GPL");